1. To investigate the association between ascariasis and hand wash investigators conducted a case-control study with 100 cases (100 children with stool-test Positive) and 100 controls (100 children Negative). Among Positives children, 50 gave a history of exposure (frequent hand washes). Among those Negatives, 25 gave a history of exposure to hand washes.
 For this study, calculate the odds ratio & interpret the result.